Mac OS - Startup Keyboard Commands

This document lists helpful keyboard commands that can be used at startup.

Startup Keystrokes

Keys Result
C Forces the Macintosh to boot from a CD, DVD, or USB thumb drive if it is present
T Starts the computer in Target Disk Mode. One can then access the internal hard drive by connecting the computer to another via firewire, thunderbolt, etc.
Shift + up arrow Start up in Safe Mode.
Spacebar Opens the Extension Manager (Mac OS 9 only)
Command Turns off virtual memory (Mac OS 9 only)
Command + R Boots from the recovery partition, if present (Mac OS 10.7 and up)
Command + S Starts the computer in Single User Mode, where the user can interact with a command terminal.
Command + Option Rebuilds the desktop (Mac OS 9 only)
Command + Option + P + R Clears PRAM
Option + Command + Shift + Delete Bypasses the current startup volume the Macintosh will try to boot from the next available device that has a valid system folder
Hold down Mouse button Ejects removable media
Option Allows you to select a boot volume on open firmware machines



Keywords:macintosh macos key commands boot sequences special keystokes startup start up   Doc ID:79
Owner:Leah S.Group:DoIT Help Desk
Created:2000-07-25 19:00 CDTUpdated:2015-07-09 12:57 CDT
Sites:DoIT Help Desk
Feedback:  9   6